There is a little more than a week to go before the primary election for mayor of New York. And polls show the city's public advocate, Bill de Blasio, has gained a comfortable lead over his Democratic rivals. De Blasio is considered one of the most liberal candidates in a crowded field, leading many to believe that Democratic voters are rejecting the centrist legacy of outgoing mayor Michael Bloomberg. NPR's Joel Rose reports.

JOEL ROSE, BYLINE: Bill de Blasio is a tall man. At 6'5", he's almost a head taller than the other Democratic candidates. And de Blasio says New York needs a mayor who thinks big to turn around decades of growing inequality.

BILL DE BLASIO: We are living a tale of two cities. It's not acceptable in any way. If we're going to end this tale of two cities, we're going to have to do big, bold things.

ROSE: Campaigning yesterday at the foot of the Brooklyn Bridge, de Blasio defended his biggest idea, universal childhood education and expanded after-school programs, which he would pay for by raising taxes on the richest New Yorkers. His critics say that plan is a long shot because it would need approval from state lawmakers, but de Blasio insists it can be done.

BLASIO: People want change in the city. They want a more inclusive and fair city. And they will look for a vision that is consistent, that doesn't change with the political winds. And I'm proud to have offered a clear, progressive vision and to have stuck with it, and I will continue to stick with it.

ROSE: De Blasio's vision seems to be connecting with relatively liberal primary voters. Several polls out this week show de Blasio surging to a 15-point lead over his nearest rivals. Jeanne Zaino teaches campaign management at New York University.

JEANNE ZAINO: De Blasio has proven himself to be a really strong debater and really strong on the stump and doing a really good job reaching out to people and saying, you know, this is who I am, and this is what I can do for you.

ROSE: De Blasio's rise has coincided with a steady slide in the polls by city council speaker Christine Quinn. That caught Zaino by surprise.

ZAINO: Here you have a woman, one of the real stars among women politicians in New York City, who looks like she could be this historic mayor if she was elected in terms of being the first woman, the first openly gay mayor, and yet she hasn't caught fire with women voters, which I think, you know, is really a huge question.

ROSE: In part, Zaino says Quinn's opponents have been successful in linking her with the city's current mayor. Quinn helped broker a deal allowing Michael Bloomberg to run for and win a third term. That has not endeared her to primary voters like Deanne Wooten(ph) of Manhattan and Ron Yampolsky(ph) of Brooklyn.

DEANNE WOOTEN: Partially, it's that she was always just right there with Bloomberg, and I'm like, you know, we've had three terms of that. So let's see what else we can do.

RON YAMPOLSKY: She might be part of the old establishment with Bloomberg. Maybe I'm going to lean towards de Blasio. Maybe.

ROSE: On the campaign trail, Quinn has been emphasizing her differences with the Bloomberg administration on things like education and homeless policy.

CHRISTINE QUINN: Myself and my colleagues in the council didn't just stand up to the mayor like the public advocate and complain, but delivered.

ROSE: Quinn picked up endorsements this week from three of the city's major newspapers, including The New York Times. If no candidate gets to 40 percent in the primary election in September, the top two vote-getters move on to a runoff election three weeks later. At a campaign stop this morning, Quinn said she still expects to be one of the top two finishers.

QUINN: I'm heading into the runoff as someone who's in a fight, and that's OK because you should fight to get into City Hall. Nobody gives you the keys to the mayor's office.

ROSE: But the latest poll shows Quinn in a virtual tie for second with former city comptroller Bill Thompson, and it looks like only one of them will be standing next to Bill de Blasio after September 10th. Joel Rose, NPR News, New York. Transcript provided by NPR, Copyright NPR.